Travelers across the United States prepared on Thursday for potential chaos ahead of widespread flight cancellations ordered by authorities due to the federal government shutdown.On Friday, airlines will begin implementing a 10-percent reduction in flights in 40 high-traffic areas of the country, complying with a Federal Aviation Administration order made on safety grounds.The shutdown has left tens of thousands of air traffic controllers, airport security staff and others without pay, causing personnel shortages.On Thursday, more than 4,000 flights were delayed, with 96 cancellations, according to the tracking service FlightAware, with travelers facing long lines at security checkpoints.Major airports were impacted, with travelers at Boston and Newark airports facing average delays of more than two hours, and those at Chicago’s O’Hare and Washington’s Reagan National more than an hour.Authorities said they wanted to act before an accident occurred.”We’re not going to wait for a safety problem to truly manifest itself, when the early indicators are telling us we can take action today to prevent things from deteriorating,” said FAA Administrator Bryan Bedford.- Peak travel season -The measures come as the country enters its busiest travel time of the year, with the Thanksgiving holiday just weeks away.The new cancellations could affect thousands of flights every day. Flight reductions will begin at four percent on Friday and rise to 10 percent, media outlets reported.Flight reductions are set to hit some of the country’s busiest airports, including in Atlanta, Newark, Denver, Chicago, Houston and Los Angeles.Implementing the order on short notice will be a challenge for airlines, which operate complex networks that rely on many moving parts and personnel.United Airlines and Delta, two of the country’s largest carriers, have said they are complying with the order but that it would not affect their international routes.United added that “hub-to-hub” flying would also not be affected, indicating cancellations might hit more local routes.Federal agencies across the United States have been grinding to a halt since Congress failed to approve funding past September 30, with some 1.4 million federal workers, from air traffic controllers to park wardens, still on enforced leave or working without pay.Many in high-stress aviation-related jobs are now calling in sick and potentially working second jobs in order to pay their bills, US Transportation Secretary Sean Duffy said on Wednesday.FAA Administrator Bedford said the situation was unprecedented.”I am not aware in my 35-year history in the aviation market where we’ve had a situation where we’re taking these kinds of measures,” he said Wednesday.”Then again, we’re in new territory in terms of government shutdowns.”

A pair of US B-52 bombers flew over the Caribbean Sea along the coast of Venezuela on Thursday, flight tracking data showed, in the fourth such show of force by American military aircraft in recent weeks.The flight comes as Washington carries out a military campaign against alleged drug smugglers in the region, deploying naval and air forces it says are aimed at curbing trafficking but which have sparked fears in Caracas that regime change is the goal.Data from tracking website Flightradar24 showed the two bombers flying parallel to the Venezuelan coast, then circling northeast of Caracas before heading back along the coast and turning north and flying further out to sea.It is at least the fourth time that US military aircraft have flown near Venezuela since mid-October: B-52s have done so on one previous occasion, and B-1B bombers on two others.The United States has also ordered the USS Gerald R. Ford carrier strike group to Latin America, has deployed F-35 stealth warplanes to Puerto Rico and currently has six US Navy ships in the Caribbean as part of what it calls counter-narcotics efforts.Washington’s forces have carried out strikes on at least 17 alleged drug-smuggling vessels — 16 boats and a semi-submersible — since early September, killing at least 67 people, according to US figures.But the United States has yet to release evidence that the vessels it has targeted were used to smuggle drugs or posed a threat to the country.Regional tensions have flared as a result of the campaign and the accompanying military buildup, with Venezuela accusing Washington of plotting to overthrow President Nicolas Maduro.

The Chan Zuckerberg Initiative, a nonprofit launched by Mark Zuckerberg and his wife aimed at curing all disease, on Thursday announced it was restructuring to focus on using artificial intelligence to achieve that goal.The move narrows the focus of the philanthropic organization founded in 2015 with a vow to devote most of the couple’s significant wealth to charitable causes, including social justice and voter rights.Zuckerberg is among the high-profile tech figures who has backed away from diversity, equality and fact-checking initiatives after US President Donald Trump took office in January.The organizaiton this year ended its diversity efforts, curbed support of nonprofits that provide housing and stopped funding a primary school that gave education and health care to underserved children, according to media reports.The philanthropic mission created by the Meta co-founder and his spouse, Priscilla Chan, said that its current priority invovles scientific teams centralized in a facility called Biohub.”This is a pivotal moment in science, and the future of AI-powered scientific discovery is starting to come into view,” Biohub said in a blog post.”We believe that it will be possible in the next few years to create powerful AI systems that can reason about and represent biology to accelerate science.”Biohub envisions AI helping advance ways to detect, prevent and cure diseases, according to the post.The mission includes trying to model the human immune system, potentially opening a door to “engineering human health.””We believe we’re on the cusp of a scientific revolution in biology — as frontier artificial intelligence and virtual biology give scientists new tools to understand life at a fundamental level,” Biohub said in the post.The first investment announced by the Zuckerbergs when the initiative debuted nearly a decade ago was for the creation of a Biohub in Silicon Valley where researchers, scientists and others could work to build tools to better study and understand diseases.Shortly after it was established, the initiative bought a Canadian startup which uses AI to quickly read and comprehend scientific papers and then provide insights to researchers.”Our multidisciplinary teams of scientists and engineers have built incredible technologies to observe, measure and program biology,” Biohub said of its progress.Meta is among the big tech firms that have been pouring billions of dollars into data centers and more in a race to lead the field of AI.